This application claims priority to Italian Application Serial No. M099A000055 filed Mar. 23, 1999, the disclosure of which is incorporated herein by reference.
The present invention relates to a safety device for a torque limiter.
The demand to render absolutely safe every machine used in production work is becoming increasingly widespread.
This trend is also increasingly followed in the field of agricultural machines, also in order to comply with international standards.
Operators handling or using agricultural implements for tilling fields and tending to the cultivations that derive from them are in fact often involved in accidents.
Specifically, it has been found that it is increasingly necessary to provide a way to mutually disconnect the agricultural implements used by tractors and the like from the power take-offs with which these tractors are equipped.
The first and immediate form of operator protection in fact consists, in case of accident, in stopping the machines being used as quickly as possible, using devices which are activated automatically but require manual resetting in order to restore the operating conditions, consequently removing the dangerous conditions.
The prior art provides many devices for protecting the elements that potentially constitute sources of possible accidents.
However, these devices consist, in most cases, of static protections which prevent access to dangerous parts, but they do not allow dynamic intervention if these devices turn out to be ineffective and a dangerous condition arises.
The aim of the present invention is to solve the above-mentioned problems of the prior art, providing a safety device for torque limiter which allows to interrupt, in a controlled way, the transmission of motion between the power take-off and the implement, stopping its operation, when abnormal and dangerous conditions occur during work, by acting on the limiter assembly, and can be reset in an absolutely manual way when the dangerous condition ends.
This aim, this object and others are achieved by a safety device for a torque limiter composed of an external body, which is rigidly coupled to the driving shaft for transmitting motion to a working implement and inside which there is a seat for accommodating an internal body which is rigidly coupled to the driven motion transmission shaft and is provided with a series of radial sliding seats for corresponding tabs which can move, in contrast with elastic means, alternatively between a centrifugal position providing engagement and transmission in corresponding slots formed in the external body and a centripetal position for disengagement from the slots and for stopping the transmission, this movement being activated by means of a corresponding centered plate which forms a protruding ring for wedging and centrifugally pushing the tabs, characterized in that means for axially pushing the plate into the configuration for forced disengagement from the tabs are interposed between the internal body and said plate.